This invention is directed to a shoe having motorized wheels, wherein the wheels may be retracted to provide a flat surface for walking.
Various designs of multifunctional footwear having retractable wheels are disclosed in the patent literature. The footwear is useful both for roller-skating and walking, depending upon whether the wheels are in an extended or retracted position. For example, the footwear may be characterized as a shoe that can be converted to a roller skate, or vice versa, a roller skate that can be converted to a shoe. Typically, each item of footwear is provided with a front axle and a rear axle, with one or two wheels per axle.
In U.S. Pat. No. 3,884,485, Wälle discloses a collapsible roller skate having wheels mounted on levers. The levers pivot in a thick-platformed roller skate from a retracted position to an extended position.
In U.S. Pat. No. 3,983,643, Schreyer et al. disclose a shoe with retractable wheels that may be used for walking or roller-skating. In one embodiment, the wheels are mounted on levers, so that the levers engage to hold the wheels in an extended position.
A shoe for walking and roller skating is shown in U.S. Pat. No. 6,343,800 issued to Clementi. The wheels retract into the sole for walking. In U.S. Pat. No. 6,386,556, Yeh discloses a roller skate having wheels mounted on levers, which can be retracted into the sole of the skate.
Roller skates having front and back wheel assemblies, which swing in an arc to retract each axle and wheel assembly into the sole of the skate, are disclosed in the following references: U.S. Pat. Nos. 6,402,162 B1; 6,523,836 B1; 6,536,785 B2; 7,036,829 B2.
Multifunctional footwear having a single retractable wheel positioned beneath the heel is shown in Chu, U.S. Pat. No. 6,629,698 B2 and Wang, U.S. Pat. No. 6,926,289 B2.
A shoe having a removable rear wheel is sold under the trademark Heelys®. The shoe is disclosed in U.S. Pat. No. 7,165,744, as well as in the other patents and patent applications of Roger R. Adams cited therein.
Various inventions directed to motorized roller skates and skateboards have been disclosed in the patent literature. For example, in U.S. Pat. No. 5,236,058, Yamet et al. disclose motor driven roller skates. The motor is an internal combustion engine, and an auxiliary wheel is provided to “jump start” the engine by the user skating under his or her own power.
Staelin et al. disclose a powered skates having an electric motor and battery pack mounted on the underside of each skate, in U.S. Pat. No. 6,059,062. A sophisticated control system operates the motor. In one embodiment, a computer receives signals from a sensor located on the skate, and the motor processes the information and controls the operation of the motor.
In U.S. Pat. No. 6,604,593 B1, Mullet discloses powered roller skates having an electric motor mounted on the back of the skates. The batteries for the motor may be carried on the skater's body. The motor may be voice-activated, to allow the skater to control its operation.
Motorized skateboards are shown in U.S. Pat. No. 5,020,621 issued to Martin and U.S. Pat. No. 5,487,441 issued to Endo et al. An electric motor mounted on the underside of the skateboard provides the power.